The subject matter disclosed herein relates generally to imaging systems, and more particularly to a method and apparatus for selecting a reference gate to generate an image.
Multi-modality imaging systems exist that scan using different modalities, for example, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT). During operation, the image quality of the conventional imaging systems may be affected by the motion of the object being imaged. More specifically, imaging artifacts may be produced by movement of the object during image acquisition. Respiratory motion is a common source of involuntary motion in mammals (e.g., people and animals) encountered in medical imaging systems and therefore is also a common source of the imaging artifacts.
One known method for reducing the imaging artifacts is to sort the image data into a plurality of gates. One of the gates is then selected as the reference gate and the remaining gates are then registered to the reference gate. However, the reference gate may not include optimal information for registering the remaining gates. For example, the reference gate may include a fewer number of pixels or pixels having a reduced pixel intensity. Thus, when the remaining gates are registered with the reference gate, the quality of the resultant image may be reduced.
Another method for reducing the imaging artifacts may include requesting the patient to hold their breath during the scan. However, because PET data, for example, may be acquired over several minutes, the patient typically has to breathe several times during the PET acquisition. Thus the patient's breathing results in patient motion which may potentially result in imaging artifacts.